I posted a few weeks back regarding this issue and hopefully some updated info will help me solve my leaky r12 system.
When the a/c is charged it puts out 38-40 degree air. Over a period of a half year or so, the charge leaks down. I put a red dye into the system to give a visual as to where it is leaking. I could not find any dye under the hood. Today I found what appears to be a red color on the insulation between the kick panel and the expansion valve. What do I have to do to safely replace o rings on the expansion valve? Any other info I would appreciate. I want to stay with r12 btw. Thanks in advance!
-Steve

__________________
1981 240D auto
1977 240D manual 300 Turbo swap
1983 300SD
1983 300TD Parts car